File buf.h is one common cause of pain in the dependencies. Many files in
the code need it to get the struct buffer definition, and a few also need
the inlined functions to manipulate a buffer, but the file used to depend
on a long chain only for BUG_ON() (addressed by last commit).
Now buf.h is split into buf-t.h which only contains the type definitions,
and buf.h for all inlined functions. Callers who don't care can continue
to use buf.h but files in types/ must only use buf-t.h. sys/types.h had
to be added to buf.h to get ssize_t as used by b_move(). It's worth noting
that ssize_t is only supposed to be a size_t supporting -1, so b_move()
ought to be rethought regarding this.
The files were moved to haproxy/ and all their users were updated
accordingly. A dependency issue was addressed on fcgi whose C file didn't
include buf.h.
Fortunately that file wasn't made dependent upon haproxy since it was
integrated, better isolate it before it's too late. Its dependency on
api.h was the result of the change from config.h, which in turn wasn't
correct. It was changed back to stddef.h for size_t and sys/types.h for
ssize_t. The recently added reference to MAX() was changed as it was
placed only to avoid a zero length in the non-free-standing version and
was causing a build warning in the hpack encoder.
Default error messages are stored as a buffer, in http_err_chunks global array.
Now, they are also stored as a http reply, in http_err_replies global array.
A dedicated function is added to check the validity of an http reply object,
after parsing. It is used to check the validity of http return rules.
For now, this function is only used to find the right error message in an
http-errors section for http replies of type HTTP_REPLY_ERRFILES (using
"errorfiles" argument). On success, such replies are updated to point on the
corresponding error message and their type is set to HTTP_REPLY_ERRMSG. If an
unknown http-errors section is referenced, anx error is returned. If a unknown
error message is referenced inside an existing http-errors section, a warning is
emitted and the proxy's error messages are used instead.
A dedicated function to parse arguments and create an http_reply object is
added. It is used to parse http return rule. Thus, following arguments are
parsed by this function :
... [status <code>] [content-type <type>]
[ { default-errorfiles | errorfile <file> | errorfiles <name> |
file <file> | lf-file <file> | string <str> | lf-string <fmt> } ]
[ hdr <name> <fmt> ]*
Because the status code argument is optional, a default status code must be
defined when this function is called.
It is now possible to use different matching methods to look for header names in
an HTTP message:
* The exact match. It is the default method. http_find_header() uses this
method. http_find_str_header() is an alias.
* The prefix match. It evals the header names starting by a prefix.
http_find_pfx_header() must be called to use this method.
* The suffix match. It evals the header names ending by a suffix.
http_find_sfx_header() must be called to use this method.
* The substring match. It evals the header names containing a string.
http_find_sub_header() must be called to use this method.
* The regex match. It evals the header names matching a regular expression.
http_match_header() must be called to use this method.
http_get_hdrs_size() function may now be used to get the bytes held by headers
in an HTX message. It only works if the headers were not already
forwarded. Metadata are not counted here.
It is now possible to set the error message to use when a deny rule is
executed. It may be a specific error file, adding "errorfile <file>" :
http-request deny deny_status 400 errorfile /etc/haproxy/errorfiles/400badreq.http
It may also be an error file from an http-errors section, adding "errorfiles
<name>" :
http-request deny errorfiles my-errors # use 403 error from "my-errors" section
When defined, this error message is set in the HTTP transaction. The tarpit rule
is also concerned by this change.
It is now possible to import in a proxy, fully or partially, error files
declared in an http-errors section. It may be done using the "errorfiles"
directive, followed by a name and optionally a list of status code. If there is
no status code specified, all error files of the http-errors section are
imported. Otherwise, only error files associated to the listed status code are
imported. For instance :
http-errors my-errors
errorfile 400 ...
errorfile 403 ...
errorfile 404 ...
frontend frt
errorfiles my-errors 403 404 # ==> error 400 not imported
All custom HTTP errors are now stored in a global tree. Proxies use a references
on these messages. The key used for errorfile directives is the file name as
specified in the configuration. For errorloc directives, a key is created using
the redirect code and the url. This means that the same custom error message is
now stored only once. It may be used in several proxies or for several status
code, it is only parsed and stored once.
http_parse_errorloc() may now be used to create an HTTP 302 or 303 redirect
message with a specific url passed as parameter. A parameter is used to known if
it is a 302 or a 303 redirect. A status code is passed as parameter. It must be
one of the supported HTTP error codes to be valid. Otherwise an error is
returned. It aims to be used to parse "errorloc" directives. It relies on
http_load_errormsg() to do most of the job, ie converting it in HTX.
http_parse_errorfile() may now be used to parse a raw HTTP message from a
file. A status code is passed as parameter. It must be one of the supported HTTP
error codes to be valid. Otherwise an error is returned. It aims to be used to
parse "errorfile" directives. It relies on http_load_errorfile() to do most of
the job, ie reading the file content and converting it in HTX.
Empty error files may be used to disable the sending of any message for specific
error codes. A common use-case is to use the file "/dev/null". This way the
default error message is overridden and no message is returned to the client. It
was supported in the legacy HTTP mode, but not in HTX. Because of a bug, such
messages triggered an error.
This patch must be backported to 2.0 and 1.9. However, the patch will have to be
adapted.
Default HTTP error messages are stored in an array of chunks. And since the HTX
was added, these messages are also converted in HTX and stored in another
array. But now, the first array is not used anymore because the legacy HTTP mode
was removed.
So now, only the array with the HTX messages are kept. The other one was
removed.
Now, we only return the start-line. If not found, NULL is returned. No lookup is
performed and the HTX message is no more updated. It is now the caller
responsibility to update the position of the start-line to the right value. So
when it is not found, i.e sl_pos is set to -1, it means the last start-line has
been already processed and the next one has not been inserted yet.
It is mandatory to rely on this kind of warranty to store 1xx informational
responses and final reponse in the same HTX message.
During startup, after the configuration parsing, all HTTP error messages
(errorloc, errorfile or default messages) are converted into HTX messages and
stored in dedicated buffers. We use it to return errors in the HTX analyzers
instead of using ugly OOB blocks.
Instead, we now use the htx_sl coming from the HTX message. It avoids to have
too H1 specific code in version-agnostic parts. Of course, the concept of the
start-line is higly influenced by the H1, but the structure htx_sl can be
adapted, if necessary. And many things depend on a start-line during HTTP
analyzis. Using the structure htx_sl also avoid boring conversions between HTX
version and H1 version.
This file will host all functions to manipulate HTTP messages using the HTX
representation. Functions in this file will be able to be called from anywhere
and are mainly related to the HTTP semantics.
